DETERMINATION OF SOIL CATION EXCHANGE CAPACITY BY A SIMPLE SEMIMICRO TECHNIQUE

METHODS OF ESTIMATING THE CATION EXCHANGE CAPACITY (CEC) OF SOILS USING VARIOUS INDEX CATIONS AND DIFFERENT SATURATION ARE DESCRIBED. A CEC TEST METHOD IS DESCRIBED WHICH DOES NOT INVOLVE REMOVAL OF THE EXCESS SATURATING CATION BY EXHAUSTIVE WASHING PROCEDURES, THUS ELIMINATING SOURCES OF ERROR IN THIS DETERMINATION DUE TO SALT RETENTION, LOSS OF THE INDEX CATION BY HYDROLYSIS, OR SAMPLE DISPERSION. IN THIS METHOD, THE SOIL SAMPLE IS TREATED WITH ONE NORMAL AMMONIUM ACETATE, THE AMMONIUM ACETATE IS REMOVED BY LEACHING WITH AN AMMONIUM NITRATE SOLUTION, AND THE TREATED SAMPLE ANALYZED DIRECTLY FOR AMMONIUM-NITROGEN BY STEAM DISTILLATION WITH 2 MOLAR SODIUM CHLORIDE AND MAGNESIUM OXIDE AFTER PARTIAL REMOVAL OF AMMONIUM NITRATE BY WASHING WITH A SMALL AMOUNT OF ISOPROPANOL. THE AMOUNT OF NITRATE NITROGEN IN THE SAMPLE IS SUBSEQUENTLY DETERMINED BY STEAM DISTILLATION OF THE SAMPLE WITH DEVARDA ALLOY, AND THE AMOUNT OF SALT RETAINED IN THE SAMPLE CORRECTED BY USE OF THE NITRATE-NITROGEN VALUE. THE METHOD IS SIMPLE AND PRECISE, IF NOT SUBJECT TO OBVIOUS ERRORS OF MANY OTHER CEC PROCEDURES, AND GIVES RESULTS SIMILAR TO ACCEPTED CEC METHODS INVOLVING USE OF AMMONIUM AS THE INDEX CATION.

  • Supplemental Notes:
    • Vol 107, No 5, PP 334-336, 1 TAB, 11 REF
  • Corporate Authors:

    N/A

    ,   United States 
  • Authors:
    • Keeney, D R
    • Bremner, J M
  • Publication Date: 0

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  • Accession Number: 00229674
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 15 2004 2:39AM